With the spread of the radio communication system, plural radio communication systems having a different standard respectively are mixed together nowadays. The need for the multimode communication apparatus that is able to deal with plural radio communication systems singly is increased. Thus, the multimode communication apparatus equipped with the communication module whose function can be varied by software has been proposed as an approach. As the function-variable multimode communication apparatus in the prior art, there was the multimode communication apparatus that includes the resource in which functions of the communication apparatus are defined and is equipped with a signal processing device that is constructed to execute the necessary signal processing by using the resource and a controller that is used to redefine other modem functions and protocol functions in the resource (see Patent Literature 1, for example). FIG. 8 shows the conventional function-variable multimode communication apparatus set forth in above Patent Literature 1.
In FIG. 8, the conventional function-variable multimode communication apparatus (mobile radio communication apparatus) receives an RF signal from a base station via an antenna 601, and transmits the RF signal to the base station. A received signal from the antenna 601 is converted into a digital received IF signal by a radio transmitting/receiving device 602, and is supplied to a signal processing device 603. Then, a digital transmitted IF signal generated by the signal processing device 603 is converted in a transmitted RF signal by the radio transmitting/receiving device 602, and is supplied to the antenna 601.
The signal processing device 603 includes hardware resources such as a processor, a memory, a logic circuit, and the like integrated as an LSI, and executes mainly the processes necessary for the transmission/reception. The resource possessed by the signal processing device 603 is controlled by a resource controller 604. This control makes the mobile radio communication apparatus respond immediately to a change in its function or specification following upon a change in using conditions. Concretely, the resource controller 604 applies control to change the software, control to change the logic circuit constituting method, or both controls to the resource in the signal processing device 603, so that the function of the mobile radio communication apparatus can be varied to a desired function.
Software utilized by the signal processing device 603 and a database for process data, etc. are held in a memory device 605. The memory device 605 reads/writes necessary programs and data under control of the resource controller 604 or the system controller 606 that controls the overall inside of the mobile radio communication apparatus. The program read from the memory device 605 is described in the signal processing device 603. An input/output device unit 607 connected to the system controller 606 includes various input/output devices acting as the interface with the user of the mobile radio communication apparatus, e.g., a microphone, a speaker, a keyboard, a display, and the like.
Patent Literature 1: JP-A-2002-335186 (FIG. 1)